B-cell non-Hodgkin's lymphoma (NHL) is the fifth most common cancer in this country with rapidly increasing incidence rates worldwide. Approximately 60% of NHL's are characterized by the t(14;18)(q32;q21) chromosomal translocation. These tumors are treated by chemotherapy and bone marrow transplantation; however, many patients relapse and become refractory to treatment. Diagnosis and post-treatment follow-up are currently performed by either karyotype analysis, Southern blotting, or polymerase chain reaction (PCR). Problems with specificity, sensitivity and low throughput, however, underscore the need for a precise, reliable, rapid method to detect tumor cells, especially in the post-treatment set up. Fluorescence in situ hybridization (FISH) has emerged as a promising method for detecting cancer cells. However, conventional FISH is a manual, labor intensive operation, making detection of cancer cells, which are typically present in low frequencies in patient samples, difficult. PROPOSED COMMERCIAL APPLICATIONS: The proposed assay will provide a rapid, sensitive, and accurate method for monitoring remission and therapy for a significant number of B-Cell Lymphoma patients. The estimated annual revenue potential is $183M.